1. Field of the Invention
This invention relates to circuits for reading data from, and writing data into, memory cells. In particular, the invention relates to a sense amplifier circuit allowing more precise control of threshold voltages during operation of a memory cell.
2. Description of the Prior Art
Typical prior art sense amplifier circuits are shown in, for example, Mukai et al., "Ultra High Speed 1K-bit-RAM with 7.5ns Access Time" 1977 ISSCC Digest of Technical Papers, pp 78, 79.
Unfortunately, the circuits described therein do not provide sufficiently fast read access time, because the read threshold must be set at substantially greater potential than the level of the non-address word lines. Furthermore, in some of these circuits it is necessary to recover the wordline that is being deaddressed at the beginning of each cycle, and this further delays read access time.